To mention someone in a post, enter @ and the first letter of an existing name on Vero, you will see appearing on a list of people starting with these letters. Select the right username you want to mention and it will turn blue in your post or in a comment. Once you have uploaded the post, the user will be mentioned underneath the content.
You can't mention or look for yourself on Vero. To look at what you posted, go to your dashboard and tap on "My Posts".